Accession Number : AD0761215

Title :   Modification and Control of Oxide Structures on Metals and Alloys: (Phase III)

Descriptive Note : Final rept. 20 Dec 1971-20 Jan 1973

Corporate Author : WESTINGHOUSE ASTRONUCLEAR LAB PITTSBURGH PA

Personal Author(s) : Svedberg, Robert C

PDF Url : AD0761215

Report Date : Feb 1973

Pagination or Media Count : 199

Abstract : The rutile structure family for oxide compounds of the type Nb(B)O4 where B = Cr, Al, or Fe have been identified as being the primary oxide phase in the scales formed on oxidation resistant Nb intermetallic compounds and Nb-Ti- Cr-Al, Nb-Fe-Al, Nb-Cr-Al-Co, and Nb-Cr-Al-Ni alloys. Along with this oxide, small amounts of either (B)2O3 where B = Cr, Al, or Fe or a CoAl2O4 spinel in cobalt containing alloys were detected. Oxygen transport rates through Nb2O3- Cr2O3, Nb2O5-TiO2, Nb2O5-ZrO2, and Nb2O5-Al2O3 were also determined using thermogravimetric techniques. Of the oxide compounds evaluated, only oxygen transport through Nb2O5-Cr2O3 was slow enough to warrent its classification as a protective scale. In addition to oxidation rate data, metallographic studies and electron microprobe studies are reported for the Nb intermetallic compounds and alloys.

Descriptors :   *CORROSION INHIBITION, *DIFFUSION, *OXIDES, *OXYGEN, *REFRACTORY METAL ALLOYS, ALUMINUM ALLOYS, ALUMINUM COMPOUNDS, CHROMIUM ALLOYS, CHROMIUM COMPOUNDS, COBALT ALLOYS, INTERMETALLIC COMPOUNDS, IRON ALLOYS, NICKEL ALLOYS, NIOBIUM ALLOYS, OXIDATION, THERMOGRAVIMETRIC ANALYSIS, TITANIUM COMPOUNDS, ZIRCONIUM COMPOUNDS, ZIRCONIUM OXIDES

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE